Adjustable safety air gauge



Oct. 19 1926.

R. v. JERNBERG Filed Nov. 10,

ADJUSTABLE SAFETY AIR GAUGE .Patented @et 19, '1926. i i

llhll'llld@ RALPH V. JERNBERC, OF WORCESTER, MASSACHUSETTS, ASSG'NOR OFONE-HALF T0 FEEDER/10K R. WILLlAll/IS, Ol? EVRCESTER, MASSACHUSETTS.

ADJUSTABLE SAFETY ATR GAUGE.

Application filed November This invention relates to an air gauge 'foruse in filling' tires although it is capable of use in any analogoussituation.

The pincipal object of the invention 675 is to provide an air gaugewhich can. be set so that when the tire is blown up 'to a certainpressure a by-pass will be connected automatically so that a signal willbe given to announce the 'fact that the predetermined pressure in thetire has been reached; to arrange this by-pass in such a manner withrelation to the air suppl?,7 that it can be depended on to act correctlyunder u all conditions and never act as an injector to provide means forchoking' the `flow of air tor the saine reason; and 'further to providethis device in such 'Form that it can be adjusted accurately andpermanently in a most simple manner to indicate the pressure for whichit is set.

The invention also involves a construction by which these advantages aresecured with a minimum oi parts and with no parts that are likely to retout ot order in use.

Reference is to be had to the accompanying; drawing` in which Figi'. 1is a longitudinal sectional view on the line A-- of Fig'. 3 of an airgauge constructed in accordance with this invention;

Fie'. 2 is a section thereo'ie on the line l-B of Fig. 1; and

Fig'. 3 is a bottom plan view showing' the scale.

I have shown the invention in a form comprising; a casina* 10 having' aninlet 11 tor connection with a supply hose 12 or the like. The conicalpassage through the inlet is 4 controlled by a valve 13 having a stemand head 14C for pressing); it down against the resistance oit' a spring15 to brine` a passa ne 16 in the valve into registration with the inletpassage. ln this way the air is admitted to a chamber 17 in the casing`10. This valve does not open widely but merely affords a passage aroundthe valve that cannot be enlarged lgreatly or quickly. lt acts as achoker to prevent a sudden rush ot air into the chamber 17. This chamberdelivers throng-h a port 18 into a socket 19 which is lined with rubberQ and lits on the valve ot the tire to deliver' air thereto. Tt isprovided with a pin 21 for operating' the tire valve as usual.

The chamber 17 is providedwith a port l0, 3.9211. Serial No. 57423.861.

25 closed by a freely reciprocating' valve 26 located in a nozzle 27 forthe purpose of allowing the air to escape from the chamber 17 throughby-pass ports 24 when the pressure in the tire has reached a certainpredetermined amount. The chamber l made large so that there will he nosudden rush o'tair past the port 25 which would hold the valve 26 lirmlvto its seat by suction, on account of acting; like an injector. This isan important feature and cooperates with the choke valve 13 i'or thispurpose. For this purpose l provide a tlat bar QS which is pivoted on across pin 29 and extends longitudinally ot the casing 10 in a socket ordepression 30 therein. This spring is adapted to engage the butt end ofthe valve plunger tor the purpose oi' holding' it to itsseat withwhatever degree or" pressure is permitted by the adjustment now to bedescribed.

On the open side oi the depression 3() is a 4guide trame 81. @n thisthere is a slide 32 formed of sheet metal and having ay button 33 on theouter side and a washer 34C on the inner side so that it is capable oitslidine' on this frame which is provided with a longitudinal slot SG.The lonpgitudinal parts ot this 'frame at the sides ot this slotconstitute the guides and the slide 32 has tongues 37 projecting; downinto the slot 36 and fitting the same so that the slide will be properlyguided. Inside the button and slide is a spring- 38 pressing on aplunger 39 which bears against the bar Q8. The pressure oit the springt.28 is adjusted b v a screw plug 40 in the end ot the button 33 so thatthe calibration can be made substantially eX- aet and permanent. along);the cuide by means ot the button so that the plunger 39 engages the bar2S at diiiierent distances from its pivotal point of support.Consequently it causes the bar to bear with different den'rees otpressure on the plunger 26, l have shown a scale l() along),` the twosides et the guide 31 indicating the pressure at which the valve 26 willbe opened so to aiti'oi'd a by-pass into the open air from the chamber17.

lt will be seen therefore that the slide can be setI in such position asto insure the lillingr of the tire up to any desired pressure and thatwhen that pressure is reached a by-pass is automatically connected toprevent much more air entering the tire and at This slide is moved 17isJ the same time giving a signal by the issue of the air through theports Qf/l. ln this Way the filling of the tire with air up to anydesired pressure is a very simple matter and there is no danger offilling it to too high a pressure. rlhereitore no time is lost inletting air out. Furthermore, there is no necessity of disconnecting theparts and testing the pressure in the tire and then connecting themagain. In this Way considerable time is saved and the tires are illedaccurately to the desired pressure instead of the pressure getting toohigh as is very frequently the case.

Although have shown and described the invention as used for `fillingtires it will be obvious that it can be employed for the purpose oflilling ballons or any other article with air, gas or vapor in order tolimit and control the pressure Within the article.

Although I have illustrated and described only a single form ot theinvention l am aware of the fact that modifications can be made thereinby any person skilled in the art Without departing from the scope of theinvention as expressed in the claims.

Therefore I do not Wish to be limited to all the details of constructionherein shown and described but what I do claim is l. In a device of thecharacter described, the combination with a casing provided with achamber having a restricted inlet with a choke valve therein foradmitting coinpressed air, gas or the lil-re and an outlet fordelivering it, the chamber having a by-pass port and being` large enoughto avoid the creation of suction inwardly at the by-pass port, by theioW of air past the port7 a valve for normally closing said port,yielding means for holding the valve closed, and adjustable yieldingmeans movable along the casing for regulating the pressure exerted onsaid valve.

2. ln a device of the character described, the combination of a casinghaving a large chamber for compressed gas or the like, a restrictedinlet having a choke valve therein, and means for delivering the air,said chamber having a port through Which the contents ot the chamber canescape to the outer air, a valve for normally closing said port. a flatspring pivoted at one end and engaging the valve to close it, a guide onthe side of the casing, a slide on the guide, linely adjustable meanscarried by the guide and adapted to engage said spring at differentdistances from its pivot to hold it against the valve, and a scale alongthe guide to show what pressure of gas inside the chamber Will berequired to displace the valve from its seat in any position of theslide.

ln testimony whereof l have hereunto aflixed my signature.

RALPH V. JERNBERG.

